Inking devices are known from the prior art which comprise an ink reservoir, an ink film pick-up roller which is capable of transferring ink to a distributor roller, and an inking roller which is capable of transferring ink from the ink reservoir to the ink film pick-up roller.
The positioning of the ink film pick-up roller relative to the inking roller is a very complex adjustment operation since it determines the homogeneity of the supply of ink to the medium to be printed which is generally constituted by a web of paper to be printed.
In order to be able to adjust the supply of ink, the ink film pick-up roller has a shaft which can be moved relative to the shaft of the inking roller. The inking devices are also provided with means for fixing the shaft of the ink film pick-up roller relative to the shaft of the inking roller.
Generally, the distance between the inking roller and the ink film pick-up roller is adjusted by shims. Shims having a specific thickness are moved in a sliding manner between the inking roller and the ink film pick-up roller. The position of the ink film pick-up roller (also referred to as “pick-up roller”) is adjusted so that it is in contact with these shims when it is in position during a printing operation. The ink film pick-up roller is then fixed in position and the shims are removed.
When the operator observes a non-uniform supply of ink over the printing width, he moves the shaft of the pick-up roller so that it is parallel with the shaft of the inking roller and adjusts it again using the shims.
This adjustment has the disadvantages of being imprecise and being susceptible to the subjectivity of the operator.